Mount for electron discharge devices



N. R. SMITH MOUNT Eon ELECTRON DISCHARGE DEVICES Fiied July 31, 1936INVENTOR NEWELL R. SMITH '&4MW

TTORNEY Patented Apr. s, 1938 UNITED STATES MOUNT FOR ELECTRON DISCHARGEDEVICES Newell R. Smith, Bloomfield, N. J., assignor, by mesneassignments, to Radio Corporation of America, a corporation of DelawareApplication July 31, 1936, Serial No. 93,534

7 Claims.

devices employing two or more independent electrode assemblies in oneenvelope.

5 The conventional multi-unit radio tube comprises one self containedelectrode assembly, or section, usually of the unit mount type of construction, supported upon the upper end of longi tudinal' support rodsrising from the stem and 10 with another electrode assembly or sectionat the lower end of the envelope supported directly on the stem. Theelectrodes and shields of the lower section which usually areindividually supported upon lead-in wires extending through the press 15 are diflicult to assemble and to maintain in fixed spaced relation.

According to my invention the elements of the lower section, which mayfor convenience be referred to as a double diode, is constructed as aunitary assembly of electrodes and shielding means. A box-like shieldreceives the electrodes and insulating spacers and is adapted to beeasily and economically assembled in the mount.

My invention is defined with particularity in the appended claims, butone embodiment thereof is described in detail in the followingspecification and accompanying drawing in which:

Figure 1 is a front elevation, partially in section, of an electrondischarge device embodying 30 my invention, and

Figure 2 is an exploded perspective View, partly in section, of a doublediode assembly embodying my invention.

The mount assembly shown in Figure 1, which 35 is particularly adaptedfor a metal envelope, comprises a stem or metal header I with electrodelead-in wires 2 sealed gas tight in glass beads in eyelets 3. The upperelectrode assembly comprises insulating spacers and 5 which support 40between them the cooperating cathode 6, grid 1 and anode 8, and whichare mounted upon support rods 9 joined at their lower ends to theheader. In this tube the cathode of the indirectly heated type extendsbelow lower spacer 5 and is .15 coated at ID with electron emittingmaterial for supplying space current to an assembly of electrodesconstructed and supported in accordance with my invention.

An assembly of diode plates adapted to cooper ate with electron emittingsurface l0 and better shown in the exploded view of Figure 2 comprises abox-like shield 20 which may as desired be either open or closed on itssides is preferably of nickel, and has an indented or recessed por- 55tion 2|, which serves to space the top of the (o1. cam-27.5)

My invention relates to mounts for electron discharge devices,particularly to multi-purpose' shield from the lower ends of theelectrode side rods of the upper section. A rectangular insulating plateor spacer 22 bears snugly in the upper portion of the shield againstrecessed portion 2| and insulating plate or spacer 23, slightly longerin one dimension than the shield, is attached 'to the lower edge thereofby ear extensions 24 from the box. In the bottom of recess 2| and inlower spacer 23,are registering openings 25 and 26 to receive the lowerend of the cathode with emitting surface l0. 'I'wo coaxial tubularanodes 21 and 28 are each positioned concentric with emitting surface l0and held upon two pairs of support rods 29 and 30 between the insulatingspacers. For convenient attachment to the support rods the anodes mayhave integral extensions 3| and 32, notched to provide offset portionsso the extensions of one anode may if desired lie in one plane and at anangle to the plane of the other anode extensions and be attached todiagonally opposite support rods. To longitudinally space the twocoaxial anodes, each extension may conveniently be of a width at its endadjacent the support rods slightly greater than the total length of thetwo coaxial anodes. Each anode is thus securely held in place upon twoopposed support rods which are held in fixed spaced relation to thecathode and to the sides of the box shield. Each anode is connectedthrough one of its support rods to a lead-in wire of the header. Thisassembly of anodes is not only rugged in construction but is easilymanufactured and assembled with the upper section -of the mount. Inassembling the mount, the shield containing the diode anodes and theirinsulating spacers, is attached to support rods 9 near the stem,preferably by welding opposite faces or extensions from the faces of theshield to the rods, and the upper assembly of electrodes is then addedby threading rods 9 through holes in 40 insulating spacers 4 and 5 andinserting cathode 6 the proper distance to bring emitting surface I0 inregistry with the diode anodes, the lower spacer 5 coming into fiatengagement with the upper face of the shield. In addition toruggedness-and simplicity of manufacture the electrode assembliesconstructed in accordance with my invention are eflectively shieldedelectrostatically, and electronically to reduce interaction between thetwo sections of the mount. Since many modifications may be made in anelectrode assembly constructed according to my invention withoutdeparting from the scope thereof, it is desired that my invention belimited only by the prior art and by the appended claims.

I claim:

1. In combination in an electron discharge device, an envelope. a stemclosing one end of said envelope, parallel support rods attached to andprojecting from said stem into said envelope, a box-like shield withopposite ends secured to said rods and having an opening in the top, anelectrode assembly resting on the top of said shield and secured to saidrods, said assembly having a cathode with its lower end pro] ectingthrough said opening into said shield, and a tubular anode in saidshield concentric with the lower end of said cathode, said anode havingradial extensions, said extensions being insulatingly secured to the topand bottom of said box.

2. An electron discharge device comprising a stem, two support rodsprojecting from the stem, 9. box-like shield secured to said supportrods near the stem and having an opening in its top, an electrodeassembly mounted on said support rods and comprising a spacer resting onthe top of said shield, and a cathode with an electron emitting surfaceprojecting into said box through said opening, spaced insulating discsheld in said shield, a tubular anode in said shield concentric with saidemitting surface of the cathode, and means for securing said anode tosaid insulating discs.

3. An electron discharge device comprising in combination a stem,parallel support rods projecting from the stem,'a rectangular sheetmetal box with its ends secured to said support rods and having anopening in the top, an electrode assembly attached to said support rodsand resting on the platform formed by the top of said box and comprisinga cathode with and an emitting surface projecting into said box throughsaid opening, an anode in said box concentric with said electronemitting surface of the oathode, said anode having extensionsinsulatingly secured to the walls of said box.

4. A multi-unit mount for electron discharge devices comprising a stemand two upstanding support rods, two transversely spaced electrodespacers attached to said support rods, a cathode extending between saidspacers and below the lower spacer, a rectangular box-like shieldattached at opposite ends to said support rods and bearing at its upperside against said lower spacer, two insulating discs in said shieldtransverse to said rods, two anodes surrounding the lower end of saidcathode and secured in spaced relation to said insulating discs.

5. An electrode assembly comprising a metal box-like shield, twoinsulating spacers at opposite sides of said shield, a cathode betweensaid spacers, two tubular coaxial anodes surrounding the cathode betweenthe spacers and each having two radial extensions, each extension beingas wide at the ends as the distance between said spacers, and means forsecuring said extensions to said spacers, the'plane oi the extensions ofone anode being at an angle to the plane of the extensions of the otheranode.

6. In combination in an electron discharge device, a rectangular metalbox, two insulating plates secured to opposite sides of said box,registering openings in said plates and the sides oi said box, a cathodeextending between and titted in said openings, two coaxial anodes heldin spaced concentric relation around said cathode between said plates,and two pairs of side rods, each rod being parallel to said cathode andengaging said plates at its ends and spaced around said openings, eachanode being secured to alterhate rods.

7. In an electron discharge device having in combination a rectangularmetal box, two insulating plates secured to opposite sides of said .box,registering openings in said plates and the sides of said box, a cathodefitted in said openings, two coaxial anodes held in spaced concentricrelation around said cathode between said plates, and two'pairs offastening means for securing each anode to said plates at spaced pointsaroundsaid openings, each anode being secured to alternate fasteningmeans.

NEWELL R. SMITH.

